lily/key-item.cc

   1 /*
   2   key-item.cc -- implement Key_item
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1996--2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8   keyplacement by Mats Bengtsson
   9 */
  10
  11 #include "item.hh"
  12 #include "key-item.hh"
  13 #include "molecule.hh"
  14 #include "paper-def.hh"
  15 #include "font-interface.hh"
  16 #include "staff-symbol-referencer.hh"
  17 #include "lookup.hh"
  18
  19 /*
  20   FIXME: too much hardcoding here.
  21  */
  22 const int FLAT_TOP_PITCH=2; /* fes,ges,as and bes typeset in lower octave */
  23 const int SHARP_TOP_PITCH=4; /*  ais and bis typeset in lower octave */
  24
  25
  26 /*
  27   FIXME: key-item should just get a list of (position, acc), and leave
  28   the thinking to other parties.
  29
  30   - TODO: put this in Scheme
  31
  32   - lots of values trivially shared (key doesn't change very
  33   often). Compute those once, and use that as cache for the rest.
  34
  35 */
  36 int
  37 alteration_pos  (SCM what, int alter, int c0p)
  38 {
  39   if (gh_pair_p (what))
  40     return gh_scm2int (gh_car (what)) * 7 + gh_scm2int (gh_cdr (what)) + c0p;
  41
  42   int p = gh_scm2int (what);
  43
  44   // Find the c in the range -4 through 2
  45   int from_bottom_pos = c0p + 4;
  46   from_bottom_pos = from_bottom_pos%7;
  47   from_bottom_pos = (from_bottom_pos + 7)%7; // Precaution to get positive.
  48   int c0 = from_bottom_pos - 4;
  49
  50
  51   if ((alter <0 && ((p>FLAT_TOP_PITCH) || (p+c0>4)) && (p+c0>1))
  52       ||
  53       (alter >0 && ((p>SHARP_TOP_PITCH) || (p+c0>5)) && (p+c0>2)))
  54     {
  55       p -= 7; /* Typeset below c_position */
  56     }
  57   /* Provide for the four cases in which there's a glitch
  58        it's a hack, but probably not worth
  59        the effort of finding a nicer solution.
  60        --dl. */
  61   if (c0==2 && alter >0 && p==3)
  62     p -= 7;
  63   if (c0==-3 && alter>0 && p==-1)
  64     p += 7;
  65   if (c0==-4 && alter<0 && p==-1)
  66     p += 7;
  67   if (c0==-2 && alter<0 && p==-3)
  68     p += 7;
  69
  70   return p + c0;
  71 }
  72
  73 /*
  74   TODO
  75   - space the `natural' signs wider
  76  */
  77 MAKE_SCHEME_CALLBACK (Key_item,brew_molecule,1);
  78 SCM
  79 Key_item::brew_molecule (SCM smob)
  80 {
  81   Grob*me =unsmob_grob (smob);
  82
  83   Real inter = Staff_symbol_referencer::staff_space (me)/2.0;
  84
  85   SCM newas = me->get_grob_property ("new-accidentals");
  86   Molecule mol;
  87   /*
  88     SCM lists are stacks, so we work from right to left, ending with
  89     the cancellation signature.
  90   */
  91   int c0p = gh_scm2int (me->get_grob_property ("c0-position"));
  92   for (SCM s = newas; gh_pair_p (s); s = gh_cdr (s))
  93     {
  94       SCM what = gh_caar (s);
  95       int alter = gh_scm2int (gh_cdar (s));
  96       int pos = alteration_pos (what, alter, c0p);
  97
  98       Molecule m = Font_interface::get_default_font (me)->find_by_name ("accidentals-" + to_str (alter));
  99       m.translate_axis (pos * inter, Y_AXIS);
 100       mol.add_at_edge (X_AXIS, LEFT, m, 0);
 101     }
 102
 103   Item *it = dynamic_cast<Item*> (me) ;
 104   if (it->break_status_dir () != RIGHT)
 105     {
 106       SCM old = me->get_grob_property ("old-accidentals");
 107
 108       /*
 109         Add half a space between  cancellation and key sig.
 110
 111         As suggested by [Ross], p.148.
 112        */
 113       Interval x (0, inter);
 114       Interval y (0,0);
 115
 116       mol.add_at_edge (X_AXIS, LEFT, Lookup::blank (Box (x,y)),0);
 117
 118       Molecule natural;
 119       if (gh_pair_p (old))
 120         natural=Font_interface::get_default_font (me)->find_by_name ("accidentals-0");
 121
 122       for (; gh_pair_p (old); old = gh_cdr (old))
 123         {
 124           SCM found = scm_assoc (gh_caar (old), newas);
 125           if (found == SCM_BOOL_F
 126               || gh_cdr (found) != gh_cdar (old))
 127             {
 128               SCM what = gh_caar (old);
 129               int alter = 0;
 130               int pos = alteration_pos (what, alter, c0p);
 131
 132               Molecule m = natural;
 133               m.translate_axis (pos* inter, Y_AXIS);
 134
 135               mol.add_at_edge (X_AXIS, LEFT, m, 0);
 136             }
 137         }
 138     }
 139
 140   return mol.smobbed_copy ();
 141 }
 142
 143
 144
 145
 146
 147 bool
 148 Key_item::has_interface (Grob*m)
 149 {
 150   return m && m->has_interface (ly_symbol2scm ("key-signature-interface"));
 151 }
 152
 153 void
 154 Key_item::set_interface (Grob*m)
 155 {
 156   m->set_interface (ly_symbol2scm ("key-signature-interface"));
 157 }